As far as I know she can receive digital signal via cable and satellite only.
Otherwise standard NTSC analogue signal.

Usually pretty crap unless she live in a good signal area.
Ah. Right. As you might imagine, she only has a typically modest income and lives in a typically modest house and cable and satellite are out of the question. So an HD TV is a bit of a luxury item to say the least. And may even be total overkill in an area where the signal is poor. So I guess she will be receiving analogue. Thanks. That gives me a bit to go on when I chat to my wife's sister on the matter.